1. Field of the Invention
This invention relates to a socket for an IC package in which a plurality of unitary contacts are brought into contact with a single IC lead at a plurality of points.
2. Brief Description of the Prior Art
Generally, in an IC socket of the type mentioned above, an arrangement is such that a single contact is brought into contact with a single IC lead at one point. In the case of an IC package having DIP type leads or gull wing type leads, or in an IC package having J-bend type leads, the contacts are brought into contact with lower surface portions or side surface portions of the leads, respectively, when the IC package is inserted in the IC socket.
In order to ensure a reliable contact, there is proposed a socket for an IC package in which a single contact has a contact element capable of contacting a side surface portion of a lead and a contact element capable of contacting a lower surface portion of the lead.
However, in the socket for an IC package of the type in which a single contact is brought into contact with a single lead at one point, inferior or insufficient contact often arises due to error in bending dimension of the lead and/or due to foreign matter interfering with the contacting point. Particularly, as the requirement for arranging the IC leads at smaller pitches and making the IC leads in more minute shape progresses and the area of the contacting point becomes extremely limited, the above-mentioned problem of inferior contact becomes apparent. Furthermore, although the above contact is soldered to a through-hole of a wiring board at a male terminal projecting downwardly of the socket or is soldered to a wiring pattern of the wiring board at the male terminal, there is a possibility that the solder will deteriorate due to vibration and/or temperature, thereby resulting in inferior contact. A solution to this problem is needed.
If a single contact is provided with a contact element capable of contacting the lead at a plurality of points, the first-mentioned problem (that is, inferior contact between each contact and each IC lead) can be solved to some extent. However, it gives rise to the problems that design of one contact element limits design of the other contact elements, and the configuration of the contact becomes overly complicated. In addition, there still remains the second-mentioned problems that solder may deteriorate due to vibration and/or temperature, resulting in inferior contact.